"Hello," a voice hollers.
"Who's there?" you shout.
"That is not important. Look up and solve the puzzle in order to exit the room. You have one minute," the voice replies. Almost instantly, the walls around you start to close in. You look up to see a 5 by 5 square as above.
You think for a moment and solved for \(x\) as quickly as you could.
You shout out a number and the walls stop closing in. What number did you shout?